The present invention relates to a grommet that is attached to a wire harness to be arranged in a motor vehicle and is inserted into a through-hole in a vehicle body panel together with the wire harness to protect, waterproof, and dustproof the wire harness at a position inserted into the through-hole.
There exist grommets that are mounted on wire harnesses arranged between a vehicle body and a door of a motor vehicle and between an engine compartment and an indoor of the motor vehicle. Additionally, vehicle body locking recess that is provided in the grommet is fitted in a through-hole in a vehicle body panel.
In the case where the through-hole in the vehicle body panel is not a circular shape but a rectangular shape, as shown in FIG. 8A, it is necessary to design a vehicle body locking recess 1a of a grommet 1 to be a rectangular shape, and it is also necessary to design a tapered tubular section 1c continued to the vehicle body locking recess 1a to be a rectangular shape in cross section. In this case, four round corners 1d of the tapered tubular section 1c receive an outward force shown by an arrow in FIG. 8B on account of forces applied to longer sides 1e and shorter sides 1f. Consequently, it is difficult to elastically deform the corners 1d inward and then the corners 1d are dented as shown by a broken line in FIG. 8B. Thus, there is a problem that there is an increase in the contact resistance between the through-hole and the grommet.
A grommet 3 adapted to be fitted in a rectangular through-hole is shown in FIGS. 9A and 9B and disclosed in JP-A-2006-127787. The grommet 3 is provided on each of four corners 3d with a pawl 4. The pawl 4 will decrease the contact area between the corner 4 and the through-hole, and thereby decrease an inserting force.
However, as shown in FIG. 9B, the pawl 4 protrudes from a whole surface of each corner 3d. Thus, the pawl 4 will impede deformation of the corner 3d and increase a contact resistance.